Bulldozer attachment for tractors



Jan. 6, 1953 A. R. HENRY BULLDOZER ATTACHMENT FOR TRACTORS 4 Sheets-Sheet l Filed June 25, 1948 INV .lml

`lan. 6, 1953 A. R HENRY 2,624,132

BULLDOZER ATTACHMENT FOR TRACTORS Filed June` 23, 1948 4 Smeets-shewv 2 Jan. 6, 1953 A. R. HENRY BULLDOZER ATTACHMENT FOR TRAcToRs 4 Sheets-Sheet 5 Filed June 23, 1948 A. AR. HENRY 2,624,132

`Ian. 6, 1953 BULLDOZER ATTACHMENT FOR TRACTORS Filed June 25, 1948 4 Sheets-Sheer 4 Ziff INVENToR, /f/fr/ f/a/f/y.

Patented Jan. 6, 1953 UNITED. STATES PAT OFFICE Albelft Ri Hely.

Ma''xirlarur.ingA

poration-1` ofJ Kansas Salina, Kans., assignortollienry Go., Inc., Topeka, Krans.,a lcorenplisatiallluns, 1948 .Serial No. 34,681..

filaims. 1.

This invention relatesfto new and useful` improvements in aV bulldozer attacln'nentL4 for trac.- tors, and has particularI referencetQ means for equalizing the vertical movement of the bulldozer blade along the entire length thereof.

In the usual bulldozer attachment for tractors, it is customary to dispose the/,bladtransversely to and just forwardly ofthe'oppositevsides of the tractor, being attached at their forward-,ends to the blade assembly'and beingA pivotally attached at their rearward endsto a portion of the tractor frame, withmeansattachedto the pushbeams or blade assembly for raising and lowering the blade. The pushbearnsI are usually attached adjacent the rearward end of the tractor to provide substantially vertical movement of the blade as it, isadjustedabove and below the ground level. With this structure, the pushbeams are of considerable length, and it is obvious that should one. end ofthe. blade encounter an obstructionv or harder ground, the natural resilience of thepushbeam andblade structurewill permit that endy of the blade to be elevated, often several inchesjmwhichv will, of course,v cause anuneven cut'.` On successive passes this error accumulates. This, bladetilting occurs especially in bulldozersknown. generally as inside bulldozerain which the` 911th-, beams are disposed between. the...tractcn'.. body and the tracks, since the connectionsoi `said beams to the blade assembly are naturallyv closer together and therefore presentlessre'sistance to tilting of theblade.

Several methodsof stabilizing the bladehave been tried. Providing extra rigid, weldedconnections between the pushbeamsv and blade assembly is only partiallyeffective, and necessarily inhibits the adjustability of the angleV ofthe blade relative to the ground;A Rigid braces extending directly between the pushbeams are impractical because of the di spositio n,l of. the tractor body betweeny the pi'ishblains,`- andf because of thev desirabilityof` *placing-tithe,blade. as close as possible to .thei'orward end ofthe tractor. Placing a separate Ehlt'frdraulc cylinder to raise and lower each pushbeam willvv have. no equalizing elect, since 4commonly ,both ofv said cylinders are operated by ,fluidt fromua common source. The fluid pressure will, of course. beA equal, throughout ther system, f and hence .the hydrauliccylinders... ,ill` uxer no ,force.. tending. to level the blade 'fteritlasbeenitilted. l

The principal object of this 1inventionistl'lere-` forelthe provision '0f v.Hieraus wberebx ,ille-.12.1.1.S11--V 2. tained substantially levelregardlessof the forces which'may beexerted. on. the blade by contact with the ground.

Another Objectis the provision, in a bulldozer attachment for tractors, including. a parof pushbeams pivotally attached to the tractor frame anda blade assembly fixed to said pushbeam, of a pair of linkages,respectively joining each of said pushbeams to said tractor frame, and a rigid connectionextendingv between corresponding members. of said linkage.

A further object is the provisiomlin a bulldozer attachment of the class described,` of, a shaft carried rotatably bythe tractor frame and extending transversely thereof to connect the pushbeams together. An arm rigidly. secured to each end of said shafthas. allink pivoted' to its free end. The opposite, end of. eachofsaid links is pivoted to the correspondingr pushbeam. adjacent the blade assembly.

Other objects are simplicityand economy of' construction, eiciency and dependability of operation, and adaptabilitytobe appliedto `various types of toolsother than' bulldozers..

With these objects in view. as welli as other objects which will appearinthe. course ofthe specification,` reference will be. had to. the drawing, wherein:

Figure 1 is aside elevation of a tractor with a, bulldozer attachment. ernbodyingvr the, .present invention attached thereto.

Fig. 2 is a plan vview of the tractor andbulldozer attachment, with parts broken away.

Fig.y 3 is an enlarged fragmentary.y section taken on line III-1110i Fig. 2, withparts broken away, showing thev blade assembly, at groundl level in solid lines, and". elevated; to the upper limit of its travelr in dotted lines.

Fig. 4 is a sectional view tahenonline IV-.IV of. Fig. 3, with parts broken' away andjwith the trackV elements omitted,

Fig. 5 is a fraameniarvsection;takenoaline V- V of Fig. 3.

Fig. 6 is an enlarged fragmentary irregular section taken ony line VIL-VI .of Fig. r3."

Like reference' cl'laracteifsy apply to similar parts througlfioutv thek severalgV views, and the numeral Z'applies to atractor having.asupp'ortl ing frame 4 anda body portion 61 A trackfrarne..

8 is disposed Yat each sidey of. the. tractor frame 4, each ofn said track frames. being. Dvotally supported adjacent, its rearward -endby an=axle I0 carried'by the` tractorframe, and .resilientlyv supported adjacent its .forward end .by a Etransfverse member such.. a5 leafgspngz, l2.l.ext ending.

outwardly from the tractor frame. Thus track frames 8 are adapted to be pivoted vertically with respect to the tractor frame about axles l, as greater or less loads are applied to spring I2 by the tractor frame. A drive sprocket |4 is carried on each axle I and is driven by the tractor engine by means not shown. An idler wheel I3 is mounted rotatably onV an axle IB carried adjacent the forward end of each track frame 8. A ground engaging track passes about each drive sprocket |4 and the associated idler wheel IB. Said tracks are further supported by a plurality of truck wheels 22 carried rotatably on the track frames, andby support rollers 24 carried by said track frames and engaging the upper reaches of said tracks.

A pair of pushbeams 2,6 each having a rectangular cross-sectional form are disposed respectively along opposite sides of the tractor, between the tractor frame and the adjacent track 20. At the rearward end of each of said pushbeams, a hollow partially spherical bearing member 28 is rigidly attached, and engages a partially spherically shaped bearing member 3Q rigidly mounted on a stub axle 32, thus forming a ball and socket joint as best shown in Fig. 5. Each stub axle 32 is fixed rigidly to a bracket 34 which is bolted or otherwise rigidly fixed to the adjacent track frame 8 just forwardly from drive sprocket I4. The ball and socket joints just described permit axial twisting as well as universal pivotal movement of the pushbeams 26, and tend to relieve torsional strains set up in the pushbeams, which occur principally when the track frames move unequal vertical distances relative to the tractor frame, while at the same time the forward ends of the pushbeams are maintained atv equal elevations by the stabilizing device hereinafter described. Pushbeams 2S are angled upwardly intermediate their ends to avoid interference with leaf spring |2.

A blade assembly 35 is disposed transversely in front of the tractor, and comprises essentially end plates 38, an arcuate moldboard 4|! extending between and attached to said end plates, and a blade 42 secured rigidly to the lower edge of said moldboard. Pushbeams 26 extend forwardly from the tractor frame, and each beam is .provided at its forward end with an outwardly projecting triangular extension 44. A forwardly projecting lug 45 formed at the forward end of pushbeam 26, and a forwardly projecting lug 48 formed at the outer portion of triangular extension 44, are adapted to project between ears 50 secured 'to the rearward face of moldboard 40 adjacent the lower edge thereof, and are pivotally attached thereto by means of bolts 52. A threaded rod 54 is pivotally secured at its lower end between ears 55 xed to each pushbeam extension 44, by means of bolt 58.4 Said rods extend upwardly and forwardly, and are pivotally connected at their upper ends to the rearward face of moldboard 4u adjacent the upper edge thereof, by means of bolts 60. Rods 54 are divided, and provided with turnbuckles 62 intermediate their ends. Blade assembly 36 is thus normally held in rigid relation to pushbeams 26, but by operating turnbuckles `G2 to lengthen or shorten rods 54, the rake or angle of the blade assembly relative to the ground may be adjusted. A ground engaging shoe 64 adapted to guide the blade while making thin cuts is carried at the lower end Vof beam 6G, said beam being carried for longitudinal adjustment by pushbeamextension 44.

. carried rotatably in bearings '|4 supported at the upper ends of lsaid plates. Each of said plates is provided with an inwardly projecting rib 'l5 Vas shown in Fig.. 4, said rib being disposed beneath bearing 'I4 and abutting at its lower end against tractor frame 4. Said ribs strengthen and stiffen plates 66, and brace them against lateral flexing. Shaft l2 is disposed transversely of the tractor and parallel toblade assembly 35, and the' end portions thereof extend outwardly beyond the sides of tractor frame 4. To each of the end portions of said shaft a sleeve 78 is rigidly fixed, and each of said sleeves is formed to present the ball portion 80 of a ball and socket connection.

A pair of hydraulic cylinders B2 are disposed respectively at each side of the tractor frame, in the same vertical planes with pushbeams 26. At its upper end each cylinder is formed to present a hollow spherical bearing 84 adapted to engage ball portion Be of sleeve 'I8 to complete the ball and socket connection. Each cylinder 82 isV provided with a piston 8S and a piston rod S8. Said piston rod extends forwardly and downwardly, and as best shown in Figs. 3 and 6, is pivotally connected at its' lower end to a connector 9@ by means of bolt 92, said bolt being parallel to shaft 12. Connector Si! is in turn pivotally connected between ears Sii which are xed rigidly to pushbeam 25 adjacent blade assembly S, by means of bolts 9G. Bolt 9S is disposed transversely to bolt 92, thus providing a universal joint between piston rod 88 and pushbeam 23. The purpose 0f ythis universal joint, and the ball and socket connectionV at the upper end of cylinder 82, is to relieve the cylinders and piston rods of lateral-stresses and strains which would otherwise-occur when the pushbeams were twisted orV forced laterally. Cylinders 82 are double acting, having fluid connections S8 and i to the respective ends thereof. Said fluid connections communicate with a suitable control valve |02 by means of which uid under pressure may bedelivered from a suitable source respectively to the lower or upper ends of cylinders 82. to raise or lower blade assembly 3S. 1

A stabilizer arm |64 having an I-section is bifurcated at its rearward end, and the sides thereof rigidly welded to sleeve 'I8 at either side of each ball and socket joint 6B- 84. Said arms extend forwardly, and are pivotally connected at their forward ends to the upper ends of links il@ by means of bolts |538. Each of said links is pivoted at its lower end to the adjacent connector 90 by means of bolt I0, as best shown in Fig. s. Y

Thus, it will be seen that the stabilizer mechanism comprising links |66, arms |04, and torque shaft i2, will not interfere with the raising and lowering of the pushbeams by cylinders 82, as illustrated by the solid and dotted line views in Fig. 8, but will effectually prevent any unequal vertical movement of the pushbeams, and will thus maintain blade assembly 35 substantially in the plane of the tractor frame. For example, if one end of the blade should strike harder ground and be forced upwardly, this movement will be transmitted to the nearer pushbeam, thence through the 'associated link |05 and arm |04, through torque shaft 12, and through the farther arm |04, link |96, and pushbeam 23 to the opposite end of the blade assembly. Furthermore, since shaft 12 is supported by bearings 1.4 adjacent each end, and said bearings are supported by plates 68, a portion of the stress exerted on either stabilizer linkage will pass directly to the tractor frame through plates 68. This decreases the effective lever arm through which the weight of the tractor exerts a force tending to tilt the blade assembly Whenever an upward force is exerted adjacent one end of said blade assembly.

Although a specific embodiment of my invention has been disclosed, many minor variations of construction and operation could be made without departing from the spirit of the invention.

What I claim is:

1. A bulldozer attachment for tractors comprising a pair of pushbeams adapted to be disposed respectively along opposite sides of a tractor and adapted to be connected pivotally at their rearward ends to a portion of said tractor, a blade assembly disposed transversely in front of said tractor and carried by said pushbeams, a shaft carried rotatably by the frame of said tractor parallel to said blade assembly, hydraulic means for raising and lowering said pushbeams disposed at each side of said tractor, said means comprising a hydraulic cylinder, piston, piston rod, and pressure connections to said cylinder, said cylinder being pivotally connected to said shaft and said piston rods being pivotally connected to said pushbeams adjacent said blade assembly, links pivotally connected to said pushbeams adjacent said blade assembly and extending upwardly therefrom, and arms rigidly secured to said shaft, the said arms being pivotally attached to the upper ends of said links.

2. A bulldozer attachment for tractors comprising a pair of pushbeams adapted to be disposed respectively along opposite sides of a tractor and adapted to be connected pivotally at their rearward ends to a portion of said tractor, a blade assembly disposed transversely in front of said tractor and carried by said pushbeams, a shaft carried rotatably by the frame of said tractor parallel to said blade assembly, hydraulic means for raising and lowering said pushbeams disposed at each side of said tractor, said means comprising a hydraulic cylinder, piston, piston rod, and pressure connections to said cylinder, a ball and socket joint connecting said cylinder to said shaft, a universal joint connecting said piston rod to the associated pushbeam adjacent said blade assembly, links universally pivoted to each of said pushbeams adjacent said blade assembly and extending upwardly therefrom, and arms rigidly secured to said shaft, the free ends of said arms being pivotally attached to the upper ends of said links.

3. A bulldozer attachment for tractors comprising a pair of pushbeams adapted to be it is apparent that .a link pivotallyconnected to disposed respectively along opposite sides of a tractor and adapted to be connected pivotally at their rearward ends to a portion of said tractor, a blade assembly disposed transversely in front of said tractor and carried by said pushbeams, a shaft carried rotatably by the frame of said tractor parallel to said blade assembly, hydraulic means for raising and lowering said pushbeams disposed at each side of said tractor, said means comprising a hydraulic cylinder, piston, piston rod, and pressure connections to said cylinder, a ball and socket joint connecting said cylinder to said shaft, a connector pivotally connected to said piston rod on an axis parallel to said shaft, said connector being pivotally carried by the associated pushbeam on an axis at right angles to said last named axis to provide a universal connection,

each of said connectors and extending upwardly therefrom, and arms rigidly secured to said shaft, the free ends of said arms being pivotally connected to the upper ends of said links.

4. In combination with a tractor having a frame and having track frames carried by said frame for independent vertical movement relative thereto, a bulldozer attachment comprising a pair of pushbeams adapted to be disposed respectively along opposite sides of said tractor between said frame and track frames, ball and socket joints connecting the rearward ends of said pushbeams to said track frames, a blade free ends of assembly disposed transversely in front of said tractor and carried by said pushbeams for pivotal movement on a horizontal axis, means for adjusting the angle of said blade assembly relative to said pushbeams, a shaft carried rotatably by the frame of said tractor parallel to said blade assembly, hydraulic means for raising and lowering said pushbeams disposed at each side of said tractor, said means comprising a hydraulic cylinder, piston, piston rod, and pressure connections t said cylinder, a ball and socket joint connecting said cylinder to said shaft, a connector pivotally connected to said piston rod on an axis parallel to said shaft, said connector being pivotally carried by the associated pushbeams on an axis at right angles to said last named axis to form a universal joint, a link pivotally connected to each of said connectors and extending upwardly therefrom, and a pair of arms rigidly connected to said shaft, the free ends of said arms being pivotally connected respectively to the upper ends of said links.

ALBERT R. HENRY.

REFERENCES CI'IKED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

